We don't have the manpower or money to kick out all 11 million illegal immigrants. Therefore, it makes sense to prioritize who we kick out.
Obama's priorities were...
Priority 1:
Threats to national security, border security, and public safety
o Persons engaged in or suspected of terrorism or espionage, or who otherwise pose threat to national security
o Convicted gang members
o Persons apprehended at the border attempting to unlawfully enter the country
o Persons convicted of a felony (other than offenses related to person’s immigration status) or
aggravated felonies
Priority 2:
Misdemeanors and immigration violators
o Persons convicted of three or more misdemeanors (other than minor traffic offenses or offenses related to person’s immigration status)
o Persons convicted of a significant misdemeanor (domestic violence, sexual abuse/exploitation, burglary, unlawful possession or use of a gun, drug distribution or trafficking, DUI)
o Persons who entered or reentered unlawfully after January 1, 2014
o Persons who have significantly abused visa programs
Priority 3:
Other immigration violators
o Persons with a final order of removal issued on or after January 1, 2014
Trump wants to spend some effort kicking out high school students, when he could be kicking out bad hombres -- that seems pretty dumb to me.